First scale the document to match the specified pixels per point, then render the rectangle given by
the upper left corner at (srcX, srcY) and srcWidth and srcHeight. This function is for rendering
a page that will be displayed. If you want to render a page that will be printed use
pageRenderToPixbufForPrinting instead

Returns True if page has a thumbnail associated with it. It also fills in width and height with the
width and height of the thumbnail. The values of width and height are not changed if no appropriate
thumbnail exists.